I believe the reason for MCAS was because the had to lower and move the engines forward. So at lower power, the forward engines make the plane nose-heavy. When the engines are near full power, the lower engines push the nose up. Compounding the difference in handling compared to the older models.
Here's the safety bulletin Boeing issued after the first crash. Even when you know what you're looking for it's hard to spot: "runaway stabilizer". It does seem they downplayed how serious the failure is, but they couldn't know how common it could be. That raises another question: Other pilots must have experienced the runaway event, but managed to gain control. What happened to those reports?
There will be lessons learnt from these crashes, in a number of fields.
[https://theaircurrent.com/aviation-safety/boeing-nearing-737...]